Escapement mechanism for type-writers.



G. W. DAVIS.

ESCAPEMENT MECHANISM FOR TYPE WRITERS.

' APPLICATION FILED APBUIB, 1910.

Patented May 30, 191-1.

, ED 'STATESPAE a i o IcE.

GEORGE'WILLIAM DAVIS, OF MONTREAL, QUEBEC, CANADA.

ESCAPEMENT MECHANISM FDR TYPE-WRITERS.

Application filed April is, 1910. Serial No. 555,590.

tendency of the former to cant thus disturbing the regularity of its action when released by the dogs carried by the dog-rocker bar.

The object of my invention is to eliminate the above mentioned defects, and it may be said to consist of the construction and several combinations of parts hereinafter described and pointed out in the claims.

For full comprehension, however of my invention reference must be had to the accompanying drawings forming a part of this specification in which similar reference characters indicate the same parts and whereinp Figure 1 is a plan view of my improved escapement mechanism applied to a typewriter, the frame of the latter and carriage being shown in dotted lines; Fig. 2is an enlarged side elevation thereof showing a portion of the frame; Fig. 3 is a sectional view taken on line A A Fig. 2; Fig. 4 isa plan view of the underside thereof. Fig. 5 is a side elevation of the arbor forming part of my invention; and Fig. -6 is a transverse sectional view of the pinion and illustrating the shoulder formed by the recess. Fig. 7

is a plan view partly broken away, of a portion of the escapement mechanism illustrating particularly the detent pawl engaging the ratchet wheel.

My improved escapement mechanism comprises a bracket Z2, situated adjacent to the e scapement racksc, on the carriage, and secured by screws d to the frame a of the machine, the said bracket presenting an up wardly offset horizontally extending arm 1 which is vertically bored at its outer end to. form a bearing. An arbor 9 having its lower end of reduced diameter to present an end thrust shoulder e is supported by the shoulder in a bearing 71, on the frame a and has the escapement wheel [mounted rigidly thereon, a screw threaded connection being preferably employed, the upperend of such arbor bearing rotatable in outer end of the arm 7...

Specification of Letters Patent. Patented Maygfl, 1911, i

the boring the Mounted loosely 'upon the arbor g and in 2 I abutment with the escapement wheel is a pinion m disposed in position to engage the escapement rack, the pinion having an annular recess n at its upper end to accommodate therigid collar 10 on the arbor and servin g as an abutment for the ratchet-Wheel 2' when it is screwed home. A pair of pawls p,'pivoted upon the underside of the ratchet-wheel and at diametrical opposite sides of the ccnter, engage the teeth of the pinion, and such teeth present radial and tangential sides 2 and 3 respectively, while the nose of each pawl is angular in form and presents a detent face t adaptedto act as an abutment retainlng the pinion against rotation in the direction indicated, and its other face permits of its riding over the teeth when the pinion rotates in an opposite direction. A pair of coiled springs 2 fastened at their opposite endsto the awls and to pins projecting from the un erside of the wheel, hold the pawls ieldingly in engagement with the teeth of the lnlon. With this relative arrangement o the ratchet-wheel and pinion the latter is free to rotate in the direction reverse to that required to release the carriage and independently of the sprocket wheel, thus permitting the carriage to be regrade rotation of the sprocket wheel and the former (12) serving as.a stop acting on the point of the tooth. This pawl is retained yieldingly in enga g osition'by aretractile spring 14 con i i dizted'at one end to the tail thereof and at its opposite end to a pin 5 carried by the base of the bracket, the spring lying substantially in alinement with the pawl. This alinement gives the awl a very delicate action and exerts but sight wear on the teeth of the ratchet-wheel.

typewriter, of an arbor rotatively supported.

thereby; an end-thrust shoulder presented by the arbor andbearingagainst the frame; a

rigid collar on the arbor; a ratchet-wheel screwed upon the arbor and abutting upon the collar; a pinion loosely mounted upon such arbor between the shoulder and the collar and formedwithan' internal recess accommodating the said collar and means adapted to operatively connect-the pinion and ratchet wheel when the former rotates in one I direction. I

2. In the escapement mechanism of a typewriter, the combination with the escapementwheel, a bracket for supporting the wheel, such bracket having a slottd enlargement, and means for releasing such wheel, of a detent pawl mounted in the said slotted \enlargement and disposed tangentially to the wheel and having its forward end notched to present a transverse detent' face adapted to be engaged by the teeth and a longitudinal face adapted to act centripetally upon the points of the teeth.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GEORGE WILLIAM DAVIS.

Witnesses:

\VILLiAM P. MGFEAT, J. A. OKEEFE. 

